Plasma separator with squeezed sealant

ABSTRACT

A blood collection and separator assembly of the type suitable for use in centrifuging blood to separate the plasma, the light phase, from the cellular portion, the heavy phase. The assembly includes a collection container and a pair of cylinders slidably disposed in the container. The first or top cylinder has a specific gravity greater than the light phase and the second or bottom cylinder has a specific gravity lighter than the heavy phase. Interposed between the cylinders are one or more layers of micro encapsulated beads of gelatin or other sealant. The average specific gravity of the first plus the second cylinders is between that of the plasma and red cells, so that the pair of cylinders float on and above the top of the heavy phase, thereby establishing the seal slightly above the interface between the light phase and heavy phase of the blood. When centrifuged the two cylinders move to the top of the packed red cells and break and squeeze out the sealant thereby forming a seal between the cylinders and the inner wall of the container slightly above the interface between the two phases of the blood.

9 Umte States Patent 1 1 1 1 3,909,419

Ayres Sept. 30, 1975 PLASMA SEPARATOR WITH SQUEEZED [57] ABSTRACTSEALANT Inventor: Waldemar y s Rutherford A blood collection andseparator assembly of the type suitable for use in centrifuging blood toseparate the [73] AssigneeI Becton, Dickinson and Company, 1 plasma, thelight phase, from the cellular portion, the

East Rutherford, NJ heavy phase. The assembly includes a collectioncontainer and a pair of cylinders slidably disposed in the Filedi 27,1974 container. The first or top cylinder has a specific grav- [21]Appl. No.: 446,367 ity greater than the light phase and the second orbottom cylinder has a spec1fic gravity lighter than the 1 heavy phase.Interposed between the cylinders are one U.S-

or morg layers of micro encapsulated beads of gelatin [51] Int. Cl? BOlD21/26 or other l t, The average specific gravity of the Field of Search23/230 13, 258-5, 292; first plus the second cylinders is between thatof the 128/2 F, 214 R, 218 M, 272; 210/83, 8 plasma and red cells, sothat the pair of cylinders float 109, 131, 359, 5 A, 518, 1316- 23, 24;on and above the top of the heavy phase, thereby es- 233/1 A, 1 26tablishing the seal slightly above the interface between the light phaseand heavy phase of the blood. When l l References Cited centrifuged thetwo cylinders move to the top of the UNITED STATES PATENTS packed redcells and break and squeeze out the seal- 3,437,266 4/1969 Patterson .2210/010. 23 am thereby forming a Seal between the Cylinders and3,647,070 3/1972 Adler 210/83 h inn r ll f h n ine g ly above h in r- 3780 935 12/1973 Lukacs et al. ZlO/DIG. 23 face between the two phases ofthe blood.

5 Claims, 2 Drawing Figures PLASMASEPARAT OR WITH SQUEEZED I SEALANT w IBACKGROUND OF'THE INVENTION" 1 It is known to separate blood intolitscornponlent parts by centrifugation, for example, theassembly-disclosedin- US. Pat. No; 2,460,641.- However, this particular assembly'does'notemploy afmeans forsealing the separated plasma or serum phase""fror'nthecellular phase? It is also known to provide assemblies for 'imanuallyseparating the plasma ,orserum phase frc pr'ri th e cellular phase forexample, as disclosed in U.S P at. Nos. 3,586,064; 3,661,265; 73,355,098; -.3,481,477; 3,512,940; a i3,693,s04. In all of thesedevicesthe serumiscollectd in ablood collection container and means areprovided for separating the plasma 'orser'um phase from the cellularpha'se employing filters, valves, transfer tubes or. the like. I I I Itis also known to provide assemblies for thesealed separation of, bloodin which a piston isactuated by centrifugalforce such as is disclosed inPaLNos. 3,508,653 and 3,779,383. These devices use either a distortablepiston made of resilient material or valve means associated with thepiston toeffect a sealed separation after centrifugation. It is alsoknown that a liquid sealant can be used for the separated portions of ablood sample as is coveredby US. Pat. No 3,780,935, but such patent doesnot disclose the two, cylinders for squeezing out the sealant of thepresent invention.

SUM ARY OF THEmvENTIO'N I It is an object of the present invention itoprovide a plasma separator assembly including a collection container anda pair ofcylinders with encapsulated sealant interposed between thecylinders slidably disposed in the container, which cylindershavespecifi'c gravities respectively greater and lower than blood s othat upon centrifugation the sealant between the cylinders will bereleased and form a seal between the cylinders and the container wallslightly above the plasma-cellular interface.

It is another object of the invention to provide a plasma separatorassembly which is economical to manufacture and can be used inconjunction with standard blood collecting equipment.

DESCRIPTION OF THE DRAWINGS For a better understanding of the invention,references are made to the drawings which illustrate the preferredembodiment of the invention herein.

FIG. 1 is a sectional, elevational view showing the plasma separatorassembly of the present invention and also illustrating a pointedcannula penetrating one of .the stoppered ends of the container throughwhich blood is introduced into the container prior to its separation.

FIG. 2 is a sectional, elevational view similar to the view of FIG. 1,showing the two cylinders and the interposed sealant forming animpervious barrier across the container at the plasma-cellularinterface.

. IDES RIPUON OFTI-IELPREFERIRED EMBODIMENT For a better ilnderstandingof the invention herein a descriptioh of thedrawing s of theillustrative embodiishad'with particular reference to FIGS. 1 and i nula14 so that-blood canb e transferred from a blood source'into thecontainer under aseptic conditions'The closures 12and'13 are preferablyself-sealing so that when the cannula is removed from the closure 12there will be no loss of blood passing through 'the penetration portionof closure 12 illustrated in FIG." 1.

Disposed in the container area pair of sliding cylinde'rs, the first ortop cyIin'der IS'having a specific grav it'yjgreater thanthe light phaseof blood (greaterth ani 1.03) andthe second or bottom cylinder 16 havingspecific gravity lower than the heavy phase of blood (less than 1.09sp.g. The average specific gravity of the first cylinder plus the secondcylinder is between the plasma and red cells, for example 1.06. The firlst cylinder carries one or more layers of rnicro encapsulated beads 17abstaining gelatin or other sealant 18.

,When operating the separator assembly of the invention herein it ispreferred that the assembly be evacuated sothat when cannula l4penetrates closure 12 blood will fillcontainer l1 automatically. It isalso contemplated to provide a separator, assemblysuitablefor use withblood collecting assembly disclosediin US. Pat, Nos. 2,460,641,3,469,572 and 3,494,352.

After,the cannula14 is withdrawn and container 11 isfilled-withbloodtheassernbly is placed ina centrifuge and the blood isseparated by initially employing moderate centrifugal force. Thisprecipitates or separates theblood cells into the lower portion ofcontainer 11 and automatically moves the cylinders .15 and 16 to floaton the plasma-red cell interface. Thereafter the rotational speed of thecentrifuge is increased which causes the squeeze between the cylindersto increase and ruptures the encapsulated beads and squeezes out thesealant (FIG. 2). The sealant surrounds the two cylinders and contactsthe inner wall of the container and forms a seal across the containerbetween the light and heavy phases of the blood.

Then the centrifugal forces are terminated and the separated bloodsample is ready for use. As desired, the

plasma can be taken from one end and/or the concentrated red cells canbe taken from the other end.

While variations of the invention herein may be had, the objectives ofthe invention have been illustrated and described.

Having described the invention, what is claimed is:

1. A separator assembly, capable of separating blood into its componentlight phase or plasma and heavy phase or cellular portion comprising:

a. a container having at least one open end which is adapted to receiveblood for subsequent separation into a light phase and a heavy phase;

b. a closure sealing the open end of the container, the closure beingformed of a self-sealing elastomeric material which is penetrable by acannula through which blood to be separated is conducted into thecontainer;

c. a pair of cylinders and rupturable capsules of sealant slidablymounted in the container, the upper cylinder having a specific gravitygreater than the light phase, the lower cylinder having a specificgravity less than the heavy phase, and the combined cylinders pluscapsules having a specific gravity between the two phases of blood; and

d. said rupturable capsules of sealant having a specific gravity betweenthe two phases of blood and being interposed between the two cylinders,whereby when centrifugal force is used the blood separates into itslight and heavy phases, the cylinders move through the light phase andcome to a 7 stop at the top of the heavy phase, and the pressure betweenthe cylinders ruptures the capsules and releases the sealant to form aseal slightly above the interface between the phases.

2. The separator of claim 1 wherein the said container comprises atubular body open at each end in which closures formed of elastomericmaterial are mounted in sealing engagement with the tubular body and thecylinders are disposed adjacent one of said closures.

3. The separator of claim 1 wherein the sealant is gelatin.

4. A separator assembly capable of separating blood into its componentlight phase, plasma, and heavy phase, cellular portion comprising:

a. a container for receiving blood having closures at each end forsealing the container;

b. a pair of cylinders plus rupturable capsules of sealant slidablymounted in the container adjacent the upper closure, the upper cylinderhaving a specific gravity greater than the light phase, the lowercylinder having a specific gravity less than the heavy phase of blood,and the combined cylinders plus capsules having a specific gravitybetween the two phases of blood; and

c. said rupturable capsules of sealant having a specific gravity betweenthe two phases of blood and being interposed between the two cylinders,

whereby when centrifugal force is used the blood separates into itslight and heavy phases, the cylinders move through the light phase andcome to a stop at the top of the heavy phase, and the pressure betweenthe cylinders ruptures the capsules and releases the sealant to form aseal slightly above the interface between the phases. 5. A separatorassembly capable of separating blood into its component light phase ofplasma and heavy 10 phase of cellular portion comprising:

a. a tubular container having two open ends;

b. resilient closure means adapted to close said ends with at least onesaid closure means capable of being penetrated by a cannula for fillingwith blood;

c. a slidable pair of cylinders plus rupturable capsules containingsealant mounted in said container, said cylinders being locatedinitially adjacent the closure opposite to that through which thecannula may penetrate, the space within the tube and between thepenetrable closure and the cylinders forming a first chamber forreceiving blood from the cannula;

d. the upper cylinder having a specific gravity greater than the lightphase of blood, the lower cylinder having a specific gravity less thanthe heavy phase of blood, and the combined cylinders plus capsuleshaving an average specific gravity between the two phases of blood; and

e. the rupturable capsules containing sealant having a specific gravitybetween the two phases of blood and being interposed between the twocylinders;

f. said slidable cylinders being adapted to move automatically to floaton the top of the interface between the phases while moderatecentrifugal force is used to precipitate the cellular portion of theblood with the displaced plasma flowing into the upper portion of thefirst chamber;

g. the cylinders being further adapted to automatically stop in theplasma slightly above the heavy phase and rupture the capsules andrelease the sealant to form a seal slightly above the interface betweenthe phases.

1. A SEPARATOR ASSEMBLY CAPABLE OF SEPARATING BLOOD INTO ITS COMPONENTLIGHT PHASE OR PLASMA AND HEAVY PHASE OR CELLULAR PORTION COMPRISING: A.A CONTAINER HAVING AT LEAST ONE OPEN END WHICH IS ADAPTED TO RECEIVEBLOOD FOR SUBSEQUENT SEPARATION INTO A LIGHT PHASE AND A HEAVY PHASE, B.A CLOSURE SEALING THE OPEN END OF THE CONTAINER THE CLOSURE BEING FORMEDOF A SELF-SEALING ELASTOMERIC MATERIAL WHICH IS PENETRABLE BY A CANNULATHROUGH WHICH BLOOD TO BE SEPARATED IS CONDUCTED IN THE CONTAINER, C. APAIR OF CYLINDERS AND RUPTURABLE CAPSULES OF SEALANT SLIDABLY MOUNTED INTHE CONTAINER THE UPPER CYLINDER HAVING A SPECIFIC GRAVITY GREATER THANTHE LIGHT PHASE THE LOWER CYLINDER HAVING A SPECIFIC GRAVITY LESS THANTHE HEAVY PHASE AND THE COMBIED CYLINDERS PLUS CAPSULES HAVING ASPECIFIC GRAVITY BETWEEN THE TWO PHASES OF BLOOD, AND D. SAID RUPTURABLECAPSULES OF SEALANT HAVING A SPECIFIC GRAVITY BETWEEN THE TWO PHASES OFBLOOD AND BEING INTERPOSED BETWEEN THE TWO CYLINDERS WHEREBY WHENCENTRIFUGAL FORCE IS USED THE BLOOD SEPARATES INTO ITS LIGHT AND HEAVYPHASES THE CYLINDERS MOVE THROUGH THE LIGHT PHASE AND COME TO A STOP ATTHE TOP OF THE HEAVY PHASE AND THE PRESSURE BETWEEN THE CYLINDERSRUPTURES THE CAPSULES AND RELEASES THE SEALANT TO FORM A SEAL SLIGHTLYABOVE THE INTERFACE BETWEEN THE PHASES.
 2. The separator of claim 1wherein the said container comprises a tubular body open at each end inwhich closures formed of elastomeric material are mounted in sealingengagement with the tubular body and the cylinders are disposed adjacentone of said closures.
 3. The separator of claim 1 wherein the sealant isgelatin.
 4. A separator assembly capable of separating blood into itscomponent light phase, plasma, and heavy phase, cellular portioncomprising: a. a container for receiving blood having closures at eachend for sealing the container; b. a pair of cylinders plus rupturablecapsules of sealant slidably mounted in the container adjacent the upperclosure, the upper cylinder having a specific gravity greater than thelight phase, the lower cylinder having a specific gravity less than theheavy phase of blood, and the combined cylinders plus capsules having aspecific gravity between the two phases of blood; and c. said rupturablecapsules of sealant having a specific gravity between the two phases ofblood and being interposed between the two cylinders, whereby whencentrifugal force is used the blood separates into its light and heavyphases, the cylinders move through the light phase and come to a stop atthe top of the heavy phase, and the pressure between the cylindersruptures the capsules and releases the sealant to form a seal slightlyabove the interface between the phases.
 5. A separator assembly capableof separating blood into its component light phase of plasma and heavyphase of cellular portion comprising: a. a tubular container having twoopen ends; b. resilient closure means adapted to close said ends with atleast one said closure means capable of being penetrated by a cannulafor filling with blood; c. a slidable pair of cylinders plus rupturablecapsules containing sealant mounted in said container, said cylindersbeing located initially adjacent the closure opposite to that throughwhich the cannula may penetrate, the space within the tube and betweenthe penetrable closure and the cylinders forming a first chamber forreceiving blood from the cannula; d. the upper cylinder having aspecific gravity greater than the light phase of blood, the lowercylinder having a specific gravity less than the heavy phase of blood,and the combined cylinders plus capsules having an average specificgravity between the two phases of blood; and e. the rupturable capsulescontaining sealant having a specific gravity between the two phases ofblood and being interposed between the two cylinders; f. said slidablecylinders being adapted to move automatically to float on the top of theinterface between the phases while moderate centrifugal force is used toprecipitate the cellular portion of the blood with the displaced plasmaflowing into the upper portion of the first chamber; g. the cylindersbeing further adapted to automatically stop in the plasma slightly abovethe heavy phase and rupture the capsules and release the sealant to forma seal slightly above the interface between the phases.